If taxpayers have not paid the correct amount at the end of the tax year (5 April), HMRC will send a P800 or a Simple Assessment tax calculation advising of how to get a refund or pay tax that is owed.
If due a tax refund, you can choose whether to receive a cheque (within 14 days), or, select the online option which takes 5 working days. If no claim is made within 45 days, a cheque will be sent out within 60 days.
Due to recent difficulties, claimants were unable to choose the online option. However, HMRC announced on 27 June that this issue has now been fixed and the service was once again open.
Any customers who have already submitted their repayment request will have the money in their bank by Thursday 2 July, or receive a cheque by Monday 13 July if they requested payment by cheque.’
You can visit the HMRC website: claim a tax refund service which explains more.